titlebar.java

采用java SWT图形库的特效代码

/*******************************************************************************
 * Copyright (c) 2005 Stefan Zeiger and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.novocode.com/legal/epl-v10.html
 * 
 * Contributors:
 *     Stefan Zeiger ([e-mail]) - initial API and implementation
 *******************************************************************************/

package com.novocode.naf.swt.custom.ishell.internal;

import java.util.Timer;
import java.util.TimerTask;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

import com.novocode.naf.swt.custom.ishell.DesktopForm;
import com.novocode.naf.swt.custom.ishell.InternalShell;


/**
 * A title bar for an InternalShell.
 * 
 * @author Stefan Zeiger ([e-mail])
 * @since Jan 21, 2005
 * @version $Id: TitleBar.java,v 1.5 2005/07/09 20:37:13 szeiger Exp $
 */

public final class TitleBar extends Canvas
{
  private static final long UPDATE_DELAY = 25;
  private static final int MINIMUM_GRAB_AREA = 2;
  private static final String ELLIPSIS = "...";
  private static final int LEFT_PADDING = 2;
  private static final int RIGHT_PADDING = 2;
  private static final int IMAGE_SIZE = 16;
  private static final int TOOL_SIZE = 14;
  private static final int TOP_PADDING = 1;
  private static final int BOTTOM_PADDING = 1;

  private int mouseDownOffsetX, mouseDownOffsetY, snapBackX, snapBackY;
  private boolean cancelled;
  private volatile long lastUpdate;
  private Timer timer = new Timer(true);
  private TimerTask timerTask;
  private final InternalShell ishell;
  private final DesktopForm desktop;
  private String text;
  private Image image;
  private final boolean styleClose, styleMax, styleTool, styleMin;
  private final Image closeImage, restoreImage, maximizeImage, minimizeImage;
  private final MenuItem restoreItem, closeItem, maximizeItem;
  private final Menu defaultPopup;
  private final Point minGrabSize = new Point(MINIMUM_GRAB_AREA, MINIMUM_GRAB_AREA);


  public TitleBar(InternalShell parent, int style)
  {
    super(parent, checkStyle(style));
    this.ishell = parent;
    this.desktop = (DesktopForm)ishell.getParent();
    this.styleClose = (style & SWT.CLOSE) != 0;
    this.styleMax = (style & SWT.MAX) != 0;
    this.styleMin = (style & SWT.MIN) != 0;
    this.styleTool = (style & SWT.TOOL) != 0;

    final Display display = getDisplay();
    final Shell shell = getShell();

    final Color gradStartColor = display.getSystemColor(SWT.COLOR_TITLE_BACKGROUND);
    final Color gradEndColor = display.getSystemColor(SWT.COLOR_TITLE_BACKGROUND_GRADIENT);
    final Color textColor = display.getSystemColor(SWT.COLOR_TITLE_FOREGROUND);
    final Color inactiveGradStartColor = display.getSystemColor(SWT.COLOR_TITLE_INACTIVE_BACKGROUND);
    final Color inactiveGradEndColor = display.getSystemColor(SWT.COLOR_TITLE_INACTIVE_BACKGROUND_GRADIENT);
    final Color inactiveTextColor = display.getSystemColor(SWT.COLOR_TITLE_INACTIVE_FOREGROUND);

    GC gc = new GC(this);
    int imgHeight = gc.getFontMetrics().getHeight()-1;
    if(imgHeight%2 == 0) imgHeight--;
    gc.dispose();

    closeImage = createMenuImage(IMAGE_TYPE_CLOSE, imgHeight);
    restoreImage = createMenuImage(IMAGE_TYPE_RESTORE, imgHeight);
    maximizeImage = createMenuImage(IMAGE_TYPE_MAXIMIZE, imgHeight);
    minimizeImage = createMenuImage(IMAGE_TYPE_MINIMIZE, imgHeight);

    setFont(createTitleFont(getFont(), styleTool));

    defaultPopup = new Menu(this);

    restoreItem = new MenuItem(defaultPopup, SWT.PUSH);
    restoreItem.setText(LocalizedStrings.get(LocalizedStrings.POPUP_RESTORE));
    restoreItem.setImage(restoreImage);
    restoreItem.addListener(SWT.Selection, new Listener()
    {
      public void handleEvent(Event event)
      {
        ishell.setMaximized(false);
      }
    });

    MenuItem minimizeItem = new MenuItem(defaultPopup, SWT.PUSH);
    minimizeItem.setText(LocalizedStrings.get(LocalizedStrings.POPUP_MINIMIZE));
    minimizeItem.setEnabled(styleMin);
    minimizeItem.setImage(minimizeImage);
    minimizeItem.addListener(SWT.Selection, new Listener()
    {
      public void handleEvent(Event event)
      {
        ishell.setMinimized(true);
      }
    });

    maximizeItem = new MenuItem(defaultPopup, SWT.PUSH);
    maximizeItem.setText(LocalizedStrings.get(LocalizedStrings.POPUP_MAXIMIZE));
    maximizeItem.setImage(maximizeImage);
    maximizeItem.addListener(SWT.Selection, new Listener()
    {
      public void handleEvent(Event event)
      {
        ishell.setMaximized(true);
      }
    });
    
    new MenuItem(defaultPopup, SWT.SEPARATOR);

    closeItem = new MenuItem(defaultPopup, SWT.PUSH);
    closeItem.setText(LocalizedStrings.get(LocalizedStrings.POPUP_CLOSE));
    closeItem.setEnabled(styleClose);
    closeItem.setImage(closeImage);
    closeItem.addListener(SWT.Selection, new Listener()
    {
      public void handleEvent(Event event)
      {
        ishell.close();
      }
    });

    addListener(SWT.Paint, new Listener()
    {
      public void handleEvent(Event event)
      {
        Rectangle r = getClientArea();
        if(r.width == 0 || r.height == 0) return;
        
        boolean active = (shell == display.getActiveShell() && ishell.isActiveShell());

        GC gc = event.gc;
        gc.setForeground(active ? gradStartColor : inactiveGradStartColor);
        gc.setBackground(active ? gradEndColor : inactiveGradEndColor);
        gc.fillGradientRectangle(r.x, r.y, r.width, r.height, false);
        
        int textLeftPadding = LEFT_PADDING;
        if(image != null)
        {
          Rectangle imageBounds = image.getBounds();
          if(imageBounds.width > IMAGE_SIZE || imageBounds.height > IMAGE_SIZE)
            gc.drawImage(image, 0, 0, imageBounds.width, imageBounds.height, LEFT_PADDING, TOP_PADDING, IMAGE_SIZE, IMAGE_SIZE);
          else
            gc.drawImage(image, LEFT_PADDING + (IMAGE_SIZE-imageBounds.width)/2, (r.height-imageBounds.height)/2);
          textLeftPadding += IMAGE_SIZE + LEFT_PADDING;
        }
        
        if(text != null && text.length() > 0)
        {
          gc.setForeground(active ? textColor : inactiveTextColor);
          String s = text;
          int availableWidth = r.width - textLeftPadding - RIGHT_PADDING;
          if(gc.textExtent(s, SWT.DRAW_TRANSPARENT).x > availableWidth)
          {
            int ellipsisWidth = gc.textExtent(ELLIPSIS, SWT.DRAW_TRANSPARENT).x;
            while(s.length() > 0)
            {
              s = s.substring(0, s.length()-1);
              if(gc.textExtent(s, SWT.DRAW_TRANSPARENT).x + ellipsisWidth <= availableWidth)
              {
                s += ELLIPSIS;
                break;
              }
            }
            setToolTipText(text);
          }
          else setToolTipText(null);
          if(s.length() > 0) gc.drawString(s, textLeftPadding, (r.height-gc.getFontMetrics().getHeight())/2, true);
        }
        else setToolTipText(null);
      }
    });

    addListener(SWT.MouseDown, new Listener()
    {
      public void handleEvent(Event event)
      {
        if(event.button == 1)
        {
          if(image != null && event.x < LEFT_PADDING + IMAGE_SIZE)
          {
            cancelled = true;
            // left-clicking on the image always shows the default popup menu
            instrumentDefaultPopup(true);
            defaultPopup.setLocation(toDisplay(0, getSize().y));
            defaultPopup.setVisible(true);
          }
          else
          {
            mouseDownOffsetX = event.x;
            mouseDownOffsetY = event.y;
            Point p = ishell.getLocation();
            snapBackX = p.x;
            snapBackY = p.y;
            cancelled = false;
          }
        }
        else if(event.button == 3)
        {
          if((event.stateMask & SWT.BUTTON1) != 0 && snapBackX != Integer.MIN_VALUE && snapBackY != Integer.MIN_VALUE)
          {
            ishell.setLocation(snapBackX, snapBackY);
            snapBackX = Integer.MIN_VALUE;
            snapBackY = Integer.MIN_VALUE;
            cancelled = true;
          }
          else
          {
          }
        }
      }
    });
    
    addListener(SWT.MenuDetect, new Listener()
    {
      public void handleEvent(Event event)
      {
        event.doit = false;
        Menu m = getMenu();
        if(m == null || m.isDisposed())
        {
          m = defaultPopup;
          instrumentDefaultPopup(false);
        }
        m.setLocation(event.x, event.y);
        m.setVisible(true);
      }
    });

    addListener(SWT.MouseDoubleClick, new Listener()
    {
      public void handleEvent(Event event)
      {
        if(event.button == 1)
        {
          if(image != null && event.x < LEFT_PADDING + IMAGE_SIZE)
          {
            if(styleClose) ishell.close();
          }
          else
          {
            if(styleMax) ishell.setMaximized(!ishell.getMaximized());
          }
          cancelled = true;
        }
      }
    });

    addListener(SWT.MouseMove, new Listener()
    {
      public void handleEvent(final Event event)
      {
        if(!cancelled && (event.stateMask & SWT.BUTTON1) != 0 && !ishell.getMaximized())
        {
          if(timerTask != null)